Handheld electric tools such as a battery-operated hammer drill provided with an electric motor as drive device, which drives a connectable cam-action mechanism in order to produce the hammer function, are conventional. On the housing side, the cam-action mechanism includes a cam-action mechanism holder provided with a circumferential, sinusoidal wave profile at the end face; to produce the hammer function, this profile cooperates with a circumferential notched disk, which is permanently joined to the drive spindle of the handheld machine tool. The drive spindle is the carrier of a tool holder and driven by the motor shaft of the electric drive motor.
When the cam-action mechanism is in operation, the friction contact between the cam-action mechanism holder and the notched disk produces heat, which must be dissipated via surrounding housing components. If the housing is made of plastic, excessive heat buildup is to be avoided.